Valve control mechanism

ABSTRACT

Actuation of a valve is prevented under certain circumstances wherein an axially reciprocable stem connected to the valve has shoulders thereon, which shoulders are selectively engageable by shiftable blocking bars.

This is a division of application Ser. No. 860,152 filed on Dec. 14,1977 now U.S. Pat. No. 4,215,964.

This invention relates to a trailer that attaches to the rear of amobile crop baler for the purpose of accumulating a load of severalbales as they issue from the baler, and holding them until the end of arow is reached so that the load can then be dumped in one pile,facilitating subsequent pickup and transport of the bales to otherlocations. The trailer of the present invention is particularlywell-suited for use in conjunction with mammoth "square" balers capableof producing bales on the order of one ton or more (see, for example,U.S. Pat. Nos. 4,034,543, to Voth, et al, and 4,037,528, to White, etal, both owned by the assignee of the present invention). It will beapparent from the description and claims which follow, however, that theprinciples of the present invention are not limited to large balers ofthat type, but may, in fact, be utilized with great effectiveness inconjunction with small, conventional balers.

One important object of the present invention is to provide for theautomatic formation of the accumulated load on the trailer, and yetpermit the operator to be the sole judge of when the accumulated load isto be dumped. In this way the operator can postpone dumping, even thoughthe load might be ready, until such time as he is lined up withpreviously dumped piles of the bales so as to facilitate the subsequentpickup and transport of the piles to other locations.

Pursuant to the foregoing, then, another important object of thisinvention is to provide for the automatic formation of a load byutilizing a transfer device which becomes automatically disabled andtemporarily inoperable to transfer another bale into a position alreadyoccupied by another bale, even though triggering mechanism for thetransfer device has already sensed that the next bale has arrived and isin position to be transferred.

A further important object of this invention is to maintain the transferdevice inoperable during dumping of the accumulated bales, and yetrender the device automatically actuated in response to completion ofthe dumping procedure.

An additional important object of the invention is to provide for suchdumping of the load to be carried out individually at differentlocations as may be desired, or all at the same time at a singlelocation.

The transfer device used in conjunction with the present invention isactuated alternately in opposite directions so as to distribute one balearriving at a receiving station in one direction and then the next balein the opposite direction. The sensing mechanism that perceives thearrival of a bale at the receiving station, however, is always actuatedin the same way and cannot itself distinguish between a bale to beshifted leftwardly from one to be shifted rightwardly. Thus, a furtherimportant object of this invention is to provide a way of alternatelyreversing the hydraulic valve associated with the transfer device foralternately opposite actuation of the latter, notwithstanding the sametype of nondiscriminatory triggering input from the sensing mechanismfor both leftwardly and rightwardly bound bales.

In the Drawings

FIG. 1 is a top plan view of a trailer constructed in accordance withthe principles of the present invention;

FIG. 2 is a side elevational view thereof illustrating more clearly theway in which the trailer is attached to the rear of a baler, and showingin one set of phantom lines the way in which the side platforms may betilted downwardly and rearwardly to dump positions, a second set ofphantom lines illustrating the position of a bale on the trailer withthe platforms in a level condition;

FIG. 3 is a transverse, cross-sectional view through the trailer takensubstantially along line 3--3 of FIG. 1;

FIG. 4 is a slightly enlarged, fragmentary, elevational view of thetrailer showing the central portion and left section thereof withcertain top structures removed to reveal details of construction;

FIG. 5 is a slightly enlarged, fragmentary, cross-sectional view takenalong line 5--5 of FIG. 4 showing portions of the operating linkageassociated with the lockout mechanism for the actuating valve of thetransfer device;

FIG.6 is a fragmentary, cross-sectional view thereof taken along line6--6 of FIG. 5;

FIG. 7 is a fragmentary, longitudinal, cross-sectional view through thetrailer taken substantially along line 7--7 of FIG. 3;

FIG. 8 is a fragmentary, transverse, cross-sectional view of the trailertaken substantially along line 8--8 of FIG. 7;

FIG. 9 is a fragmentary, horizontal, cross-sectional view takensubstantially along line 9--9 of FIG. 8;

FIG. 10 is a vertical, cross-sectional view of the rearmost end of thetrailer similar to FIG. 7, but showing the sensing and triggeringmechanism in an actuated position as contrasted with the unactuatedcondition in FIG. 7;

FIG. 11 is a fragmentary, detail view illustrating the construction andfunction of the sensing elements associated with the side platforms;

FIG. 12 is a view similar to FIG. 11, but illustrating the relationshipof the components as the side platform is returned to its level positionfrom a dumping position thereof;

FIG. 13 is a fragmentary, vertical, cross-sectional view of the trailertaken substantially along line 13--13 of FIG. 1 and illustrating the wayin which the side platforms are attached to the frame and releasablyheld in their level positions; and

FIGS. 14-19 are diagrammatic illustrations of the way in which thebale-accumulating operations take place as related to the variousmovements of the mechanisms employed in accomplishing such formation.

In FIGS. 1 and 2 the trailer 10 is shown attached to the rear end of abaler 12 having a bale discharge chute 14. A pair of links 16 onopposite sides of the baler 12 pivotally interconnect the chute 14 andthe trailer 10 so that the assembly thus formed can articulate about atransverse horizontal axis in response to changes in ground contour. Acentral fore-and-aft extending tongue 18 rigid to the trailer 10 ispivotally connected to the rear of the baler 12 to aid in theinterconnection of the two implements.

The trailer 10 has a rigid frame 20 (FIG. 4) that includes a long,rectangular central section 22 and a pair of laterally outboard sections24 (only one being visible in FIG. 4). A substantially centraltransverse frame member 26 spanning the entire width of the frame 20 hasa pair of depending castor wheel assemblies 28 attached thereto atlaterally outboard positions of the central frame section 22.

A central bale-receiving station aligned directly behind the chute 14 isdefined by a central platform 30 overlying the central frame section 22.The platform 30 has a pair of generally planar portions 32 and 34 spacedapart in a fore-and-aft direction. A pair of laterally outboard stationson opposite sides of the central platform 30 are presented by left andright side platforms 36 and 38, respectively (viewed from the rear ofthe machine), such side platforms 36, 38 being displaced slightlyrearwardly of the forwardmost end of the central platform 30 as perhapsseen best in FIGS. 1 and 2.

Each of the side platforms 36, 38 is mounted for independent swingingmovement in a vertical direction between the substantially levelposition illustrated in solid lines in FIG. 2, and the downwardly andrearwardly inclined position illustrated in phantom lines in that Fig.The central platform 30, however, does not tilt. Each of the platform36, 38 is swingable about the longitudinal axis of the transverse framemember 26 (FIG. 13), which is of cylindrical, tubular configuration. Thecenter of gravity of each platform 36, 38 is so disposed that they aregravity-biased toward their tilted positions, yet each is provided witha tension spring 40 interconnecting the same with the outboard framesection 24 so as to yieldably retain the platforms 36, 38 in their levelpositions.

Although the springs 40 are sufficient to retain the unloaded platforms36, 38 in their level positions, when massive bales are placed thereon,such as on the order of one ton or more, the springs 40 are notthemselves sufficient to retain the platforms 36, 38 in their levelpositions, this being accomplished instead by a pair of releasablelatches 42 (FIGS. 13, 3 and 2) for the two platforms 36, 38. Each latch42 includes a depending catch 44 that is rockably secured to thecorresponding platform 36, 38 by a transversely extending pivot 46. Thecatch 44 is notched at its lower end and biased by a torsion spring 47toward and receives a rockshaft 48 on the outboard frame section 24.Rockshaft 48 has a small square cam 49 (FIG. 13) on its backside thatengages the proximal lower portion of catch 44 when rockshaft 48 isrotated clockwise viewing FIG. 13, thereby to cam the catch 44 off therockshaft 48 and release latch 42. A depending crank 50 is rigidlysecured to the rockshaft 48 for operating the latter, and a rope (notshown) may lead from the lower end of the crank 50 up to the driver'sseat of the tractor associated with the baler and trailer for manualactuation by the driver, there being a tension spring 52 connectedbetween the crank 50 and the outboard frame section 24 so as toyieldably bias the crank 50 toward the position illustrated in FIG. 13,wherein the catch 44 is engaged with the rockshaft 48. Members 54 and56, respectively, on the platforms 36, 38 and the outboard frame section24 abut one another when the platforms 36, 38 are in their levelpositions as illustrated in FIG. 13 so as to prevent the return spring40 from swinging the platform 36 or 38 beyond its level position.

A sensing and triggering treadle 58 is swingably connected via a pianohinge 60 to the rear of the central frame section 22 for verticalswinging movement between the raised position of FIG. 7 and thedepressed position of FIG. 10. Depending from the treadle 58 through thecentral frame section 22 is a pair of laterally spaced, relativelynarrow plates 62 that are rigidly affixed to the treadle 58 for swingingmovement with the latter. A telescoping rod 63 interconnects the lowerend of the plates 62 with the forwardly disposed lower end of a pair ofimmobile diagonally extending straps 64 that are rigid to the centerframe section 22, a coil spring 66 surrounding the telescoping rod 63and being trapped between the two sets of plates 62 on the one hand andstraps 64 on the other hand so as to yieldably bias the treadle 58toward its upward position.

The two depending plates 62 have a cross pin 68 therebetween midwaybetween their upper and lower ends which is disposed for operatingengagement with the rear end of a fore-and-aft extending latch lever 70when the treadle 58 is depressed. Latch lever 70 in turn is swingablymounted on the central frame section 22 by a horizontal pivot 72 forreleasable latching engagement with a crosspiece 74 between a pair ofdepending levers 76. A downwardly facing notch 78 in the lower edge ofthe latch lever 70 is engageable with the crosspiece 74 to releasablyhold the levers 76 in the rearwardly disposed position of FIG. 7, thelevers 76 being swingably attached to the central frame section 22 by ahorizontal pivot 80.

A bifurcated depending component 82 forms a part of the latch lever 70and serves as a rear limiting shoulder for a compression spring 84 thatencircles a fore-and-aft extending bar 86 having a rear pivot 88 withthe depending plates 62 and a front pivot 90 with the depending levers76. The front pivot 90 serves as the opposite limiting shoulder for thecoil spring 84, and also serves as the guide pin for a fore-and-aftextending slot 92 in the forward portion of the bar 86. The dependinglevers 76 are thus biased yieldably forwardly by the spring 84.

A push rod 94 is connected between the two levers 76 slightly above thehorizontal pivot 90 and extends forwardly therefrom beneath the centralplatform 30 to a position slightly rearwardly of the transverse framemember 56, terminating in a forwardmost operating tip 96 (FIG. 7). In sodoing, the rod 94 passes through a vertically elongated opening 98 in agenerally U-shaped component (viewed in elevation), hereinafter referredto as a locater 100, that is mounted by a vertical pivot 102 on thecentral frame section 22 for horizontal swinging movement between a pairof laterally opposed stops 104 and 106 (FIG. 4). A short coil spring 108(FIG. 7) biases the rod 94 downwardly to the lower end of the opening98, and because of the lateral confinement of rod 94 within the opening98, the tip 96 is swingable with the locater 100 between its two extremepositions, the connection of the rear end of the rod 94 with thedepending levers 76 being loose enough to permit such horizontal movingswinging movement of the rod 94.

The tip 96 is normally engaged with one or the other of a pair ofupright, triangular shoulder pads 110 and 112 which form part of ahorizontally swingable lever 114 mounted on the central frame section 22by a vertical fulcrum 116. The position of the stops 104 and 106 for thelocator 100 is such that when the latter is against the stop 104, thetip 96 will be on the right side of the fulcrum 116 (as viewed from therear of the machine) against the pad 112, while when the locater 100 isagainst the opposite stop 106, the tip 96 will be on the left side ofthe fulcrum 116 against the pad 110. Thus, forwardly directed pushingforce in the rod 94 is transmitted to either side of the fulcrum 116 ofthe lever 114, depending upon the position of the locater 100.

A hydraulic valve 118 has a long fore-and-aft extending stem 120 thereofreciprocable axially between a pair of opposite extreme positions onopposite sides of a centered, neutral position. The rearmost end of thestem 120 is joined by connector 122 with the lever 114 on the left sideof the fulcrum 116 so that swinging movement of the lever 114 results inshifting of the stem 120 between its neutral and operating positions asabove-described. The valve 118 forms part of the hydraulic controlcircuit for a double-acting cylinder 124 having a ram 126 pivotallycoupled at its outer end with one link 128 of a four-bar linkage 130(FIG. 4) associated with a bale transfer device 132. The link 128 islocated below the central platform 30 for swinging movement about avertical pivot 136, and the second link 134 of linkage 130 is similarlyswingable about a vertical pivot 138. Transfer device 132 takes the formof a fore-and-aft extending beam 140 pivotally connected at its oppositeends by pivots 142 and 144 to the linkage 130.

The beam 140 is located at a level slightly above the upper surface ofthe central platform 30, while the links 128 and 134 extend beneath thelatter in underlying relationship to the planar portion 32 and 34thereof. The length of ram 126 is such that, when extended, it swingsthe transfer beam 140 from the left side of the central platform 30 asillustrated in FIG. 1 to the opposite side thereof next adjacent theside platform 38, all the while maintaining the beam 140 parallel withthe direction of travel of the machine.

The linkage 130 is also provided with a fore-and-aft extending tie bar146 that is pivotally connected at its front end to the link 128 by apivot 148, and is likewise pivotally connected at its rear end to thelink 134 by a pivot 150. The tie bar 146 assures that the transfer beam140 will indeed remain in its fore-and-aft disposition even as the samepasses over center during its back-and-forth swinging motion during thebale transfer process.

A pentagonal plate 152 is secured to the tie bar 146 for movementtherewith as the same shifts generally fore-and-aft during actuation ofthe transfer device 132, and such plate 152 has a pair of upstandingprojections 154 and 156 that are spaced apart in a fore-and-aftdirection and are interconnected by a strap 158 located a short distanceabove the upper surface of the plate 152. The lever 114 is receivedwithin the space between the strap 158 and the top surface of plate 152and is disposed to be acted upon by the projections 154 and 156 after apredetermined amount of lost motion in a fore-and-aft direction of theplate 152.

On the bottom of the plate 152 a pair of depending limits 160 and 162are provided that are likewise spaced apart in a fore-and-aft directionand which likewise have a strap 164 interconnecting the same and spaceda short distance below the bottom surface of the plate 152. A crank 166fixed to the locater 100 beneath the lever 114 extends through and isreceived within the space between the strap 164 and the bottom surfaceof the plate 152 to be acted upon by the limits 160 and 162 after apredetermined amount of lost motion movement by the plate 152 duringswinging of the transfer device 132 by the hydraulic cylinder 124.

The valve stem 120 of the hydraulic valve 118 carries a pair oftruncated cones 168 and 170 that are spaced apart axially of the stem120 to form a pair of spaced shoulders. As illustrated, the cones 168and 170 have their chamfered or tapered portions generally facing oneanother, and they form a portion of what may broadly be referred to as"lockout mechanism" to prevent actuation of the valve 118 under certaincircumstances. In addition to the cones 168 and 170, the lockoutmechanism also includes a pair of transversely extending abutments inthe form of blocking bars 172 and 174, the bar 172 being associated withthe left side platform 36 and the bar 174 with the right side platform38. The bars 172 and 174 are supported beneath the central frame section22 for reciprocation transversely of the latter and are disposed in sucha fore-and-aft relationship with the cones 168 and 170 that they can beinserted into the gap 176 between the cones 168, 170 when the stem 120is in its neutral position as illustrated in FIG. 4. Note that bar 174is located slightly forwardly of the bar 172 so that they clear eachother and overlap in a fore-and-aft direction when they are insertedinto the gap 176. Note further that the innermost ends of both bars 172,174 have bevels 172a and 174a along their lower edges (FIG. 3) forfacilitating entry into the gap 176.

The bars 172, 174 extend laterally outwardly from the cones 168, 170 toa position just slightly outboard of the central frame section 22 wherethey are joined to the lower end of respective depending cranks 178.Each of the cranks 178 is, in turn, rigidly affixed at its upper end toa fore-and-aft extending shaft 180 that is journaled to the centralframe section 22 so as to adapt the cranks 178 for in-and-out swingingmovement about the longitudinal axes of the shafts 180. The shafts 180extend rearwardly from the cranks 178 to a position just behind thetransverse frame member 56, where a second depending crank 182 connectseach shaft 180 with a transversely extending push-pull rod 184 leadinglaterally outboard to the side platforms 36 or 38. The laterallyoutboardmost end of each rod 184 is connected to the lower end of anoperating crank 186 that is swingable with a sensor element 188 about afore-and-aft axis, the element 188 normally projecting upwardly throughthe corresponding side platform 36 or 38 and being joined to the crank186 by virtue of a common fore-and-aft extending rockshaft 192 definingsaid axis.

Each sensor element 188 is vertically aligned with an enlarged cutout194 in its corresponding side platform 36 or 38 so that the element 188can indeed project upwardly through the platform 36 or 38 when the sameis in its level position. The element 188 is, however, also depressibleto a lowered position upon depression by an overlying bale asillustrated in FIG. 11. Yieldable means in the form of a leaf spring 196(FIGS. 5 and 6) projecting laterally inwardly from each outboard framesection 24 frictionally engages the corresponding crank 186 so as toyieldably hold the corresponding sensor element 188 in either of itsraised or depressed positions.

Each of the sensor elements 188 is mounted on the frame 24 of thecorresponding side platform 36 or 38 and therefore does not swing withthe latter during bale dumping. Return means 198 (FIGS. 11 and 12),however, constructed somewhat similar to the elements 188, is mounted oneach of the platforms 36 and 38 for movement therewith during suchswinging. Each of the return means 198 includes a sensing plate 200 thatis swingably supported on the corresponding platform 36 or 38 by afore-and-aft extending pivot 202 for movement between a normal position(FIG. 12) projecting upwardly through the cutout 194 and a depressed,substantially level position (FIG. 11). A coil spring 204 yieldablybiases each of the plates 200 toward its upwardly projecting normalposition wherein a stop 206 is engaged by a depending leg 208 associatedwith the plate 200. The leg 208 is so positioned that, when the plate200 is cocked upwardly as in FIG. 12 during the return of thecorresponding platform 36 or 38 to its level position, the leg 208 isdisposed to engage and operate a proximal leg 210 associated with thecorresponding sensor element 188 so as to overcome the resistance of theleaf spring 196 and return the element 188 to its upwardly projectingposition.

Operation

The operation of the trailer 10 may be briefly summarized as follows. Asa bale issues from the discharge chute 14, it inches its way rearwardlyonto the central platform 30 until such time as it fully depresses thetreadle 58 at the rear of the machine. The treadle 58 will normally befully depressed only after the full bale has been completely dischargedfrom the chute 14 and a substantial portion of the next succeeding baleis protruding from the same into engagement with the central platform30. Once the treadle 58 is depressed, it actuates the hydraulic valve118 which in turn supplies fluid to the cylinder 124 to actuate thetransfer device 132. The bale is thereupon swept rightwardly orleftwardly by the transfer device 32, depending upon the latter'simmediately preceding position, so as to load one or the other of theside platforms 36 and 38. This clears the central platform 30 for thearrival of the next succeeding bale which likewise depresses the treadle58 and causes the transfer dvice 132 to sweep in the opposite directionand load the second bale onto the other of the side platforms 36 or 38.This, again, clears the central platform 30 so that a third bale may bereceived, by which time the driver should be near the end of the row sothat the accumulated load can be dumped. By first dumping the two sideplatforms 36 and 38, actuation of the transfer device 132 will thereupondistribute the third bale onto one of the empty platforms 36 or 38 whichcan then be dumped so that all three bales are left in a pile at thesame location. The driver is then ready to head down along the next rowto accumulate three more bales in the same manner as above-described.

A more detailed description of the accumulation and dumping process maybe understood by reference in part to the diagrammatic illustrations inFIGS. 14-19. Prior to any bales being accumulated on the trailer 10, thetreadle 58 is fully raised as in FIG. 3, the sensing elements 188 andthe sensor plates 200 are tipped upwardly to project through the cutouts194, and the blocking bars 172, 174 are retracted out of the gap 176between the control cones 168, 170, the valve stem 120 being in itsneutral position at that time as illustrated in FIG. 4.

As the first bale progresses rearwardly and depresses the treadle 58,nothing happens until the cross pin 68 sufficiently depresses the rearend of the latch lever 70 to lift the notch 78 thereof off thecrosspiece 74, thereby enabling the spring 84 to snap the dependinglevers 76 forwardly. This thrusts the tip 96 of actuating rod 94 againstthe pad 112 of lever 114 with sufficient force to swing the lattercounterclockwise viewing FIG. 14 so as to in turn pull rearwardly on thevalve stem 120. This corresponds to the condition of things in FIG. 14.

Such rearward actuation of the valve stem 120 permits pressurized fluidto enter the hydraulic cylinder 124 and extend the ram 126 so as tocause the transfer device 132 to sweep from left to right across thecentral platform 30, depositing the first bale onto the right sideplatform 38 in the process. Once the bale is pushed off the treadle 58,the spring 66 returns the same to its upwardly cocked position, liftingthe cross pin 68 from the latch lever 70 and pulling the dependinglevers 76 rearwardly so as to reposition the crosspiece 74 within thelatching notch 78. This, of course, also pulls the actuating rod 94rearwardly and resets things for the next bale.

Such return of the actuating rod 94 to a rearward position is notimmediate, however, and in fact is delayed until after the transferdevice 132 has completed its full sweep. Thus, as the transfer device132 sweeps rightwardly, the lever 114 remains in its FIG. 14 position,as does the locater 100, until the end of the sweep cycle is approached,whereupon the rear limit 160 of the forwardly moving plate 152 engagesthe crank 166 to swing the locater 100 clockwise to the opposite side ofthe fulcrum 116 to the extent illustrated in FIG. 15. This also carriesthe tip 96 to the left side of the fulcrum 116, and inasmuch as thelever 114 remains in its FIG. 14 position until a short time later,transfer of the tip 96 to the left side of the fulcrum 116 isaccomplished without shutting off the valve 118 by having the tip 96enter a space 212 between the triangular pads 110 and 112, thereuponriding upon an uppermost, non-force-transmitting surface or edge 110a ofthe pad 110. Then, when the rear projection 154 engages and swingsforwardly the lever 114 to shut off the valve 118 and terminate thesweeping stroke of the transfer device 132, the tip 96 falls down to aposition just rearwardly of the pad 110 in force-transmittingrelationship therewith. Note that the vertically elongated opening 98 inthe locater 100 permits such up-and-down movement of the tip 96 underthe influence of the tension spring 108.

The lever 114, the actuating rod 94, and the valve stem 120 thus comeinto the position of FIG. 15. In the meantime, however, the sensingplate 188 associated with the right side platform 38 has been depressedby the first bale moving onto the latter (so also has the adjacentsensing plate 200 as illustrated in FIG. 11). Thus, the right blockingbar 174 has been shifted inboard into the gap 176 between the cones 168,170. Until the blocking bar 174 is subsequently removed, the valve 118cannot again be actuated to sweep the transfer device 132 toward theright side platform 38, even though the transfer device 132 willsubsequently be in its leftmost position, otherwise ready to make suchrightward movement.

With the components thus in the condition illustrated in FIG. 15,arrival of the second bale onto the central platform 30 causes thetreadle 58 to be depressed in the above-described manner. This time,although movement of the actuating rod 94 is again forwardly, the lever114 is rotated clockwise viewing FIG. 15 out of its neutral positioninasmuch as the tip 96 of rod 94 applies force on the left side of thefulcrum 116. Therefore, the valve stem 120 is pushed forwardly so as toactuate valve 118 in the opposite direction as illustrated in FIG. 16.This causes the ram 126 of the cylinder 124 to be retracted, therebysweeping the transfer device 132 leftwardly across the platform 30 todistribute the second bale onto the left side platform 36, the transferdevice 132 ending up adjacent the left side platform 36 as illustratedin FIG. 17.

As the plate 152 moves rearwardly during leftward swinging of thetransfer device 132, the crank 166 of locater 100 is engaged andoperated by the front limit 162 so as to swing the locater 100, and thusthe tip 96, in a counterclockwise direction over to the right side ofthe abutment 116. As before, inasmuch as such shifting of the tip 96occurs prior to return of the valve stem 120 to its neutral position,the tip 96 enters the space 212 between the pads 110 and 112, thereuponriding up along the non-force-transmitting upper edge 112a of the pad112. When the lever 114 is thereupon engaged and operated by therearwardly moving front projection 156 so as to swing the lever 114counterclockwise to its neutal position, the tip 96 falls down to aposition just rearwardly of the pad 112 in force-transmitting positiontherewith.

Note that as the second bale is distributed onto the left side platform36, it engages and depresses the sensor element 188 and the sensingplate 200 associated with the platform 36. As a result of depression ofthe sensing element 188, the left blocking bar 172 is shifted inboardinto the gap 176 as illustrated in FIG. 17. In this position, theblocking bar 172 precludes movement of the stem 120 in a forwarddirection because of interference with the rear cone 170. In fact,inasmuch as both blocking bars 172 and 174 are in place within the gap176, actuation of the stem 120 is prevented in either direction.

With the transfer device 132 thus in its leftmost position and thecentral platform 30 cleared, the latter is again ready for the arrivalof the third bale. The third bale emerges from the chute 14 anddepresses the treadle 58. However, even though the third bale is thusready to be transferred laterally as illustrated in FIG. 18, the valve118 cannot be actuated because the blocking bars 172 and 174 are inplace. Parenthetically, it should be noted that depression of thetreadle 58 is permitted, notwithstanding the fact that the rod 94 cannotbe thrust forwardly, because the slot 92 in the bar 86 at the rear ofthe machine allows the bar 86 to be pushed forwardly even though thelevers 76 remain substantially stationary. Spring 84 behaves as a reliefspring under these circumstances.

Noting that the trailer 10 is fully loaded, the operator may then beginthe dump cycle by pulling the ropes (not shown) associated with eitheror both of the latches 42 for the side platforms 36, 38. If both of thelatches 42 are released, then both platforms 36, 38 will begravity-biased to their dumping positions illustrated in phantom linesin FIG. 2, permitting the bales to slide thereoff onto the ground asslight forward movement of the trailer 10 is continued. Return springs40 swing the emptied platforms 36 and 38 back to their level positions,relatching the latches 42 in the process.

It is important to note that during the dumping procedure, the sensorelements 188 associated with the platforms 36 and 38 remain depressed byvirtue of the leaf springs 196, even though the weight of the bales isrelieved from the sensor elements 188 because of the fact that the balesswing upwardly with the platforms 36, 38 while the sensors 188 remainbehind with the frame 20. As the platforms, 36 38 are then returned totheir level positions, the leg 208 of each return means 198 on theplatforms 36, 38 strikes the inboard-projecting leg 210 associated withthe corresponding sensor element 188 to overpower the leaf spring 196and slip the sensor element 188 back to its upwardly cocked position.This manifestly withdraws both the blocking bars 172, 174 from the spacebetween the cones 168, 170, permitting the "relief" spring 84 at therear of the trailer 10 to snap the operating rod 94 forwardly andactuate the valve 118. Thus, the transfer device 132 then sweepsrightwardly to deposit the third bale on the right platform 38,whereupon the third bale may then be dumped from the platform 38 in themanner above-explained. Upon return of the platform 38 to its levelposition, all components are thereupon in condition for the formation ofa new three-bale load.

It is significant to note that, as shown in FIG. 19, both bales on theside platforms 36, 38 need not be dumped in order to ready the transferdevice 132 for operation, it being only necessary to empty thatparticular side platform 36, 38 which the sequence of events hasdetermined to be the recipient of the next bale from the centralplatform 30. Thus, as illustrated in FIG. 19, upon dumping the rightplatform 38, the right blocking bar 174 is withdrawn from between thecones 168 and 170, permitting the valve stem 120 to be shiftedrearwardly so as to correspondingly sweep the transfer device 132 towardthe right platform 38 and load the same with the bale.

It is contemplated that a signal system (not shown) of suitable form maybe located in the cab of the towing vehicle so as to advise the driverof the status of the various procedures occurring on the trailer 10behind him. This may be particularly significant in the event that hisvision to the rear is obscured by the presence of the baler 12.

Thus, a switch 214 (FIG. 4) might be provided in conjunction with thetreadle 58 to control the actuation of a signal device which wouldindicate that a bale has arrived on the central platform 30. Likewise, asecond switch 216 may be actuated by the transfer device 132 when thelatter is in its leftmost position so as to indicate said position;correspondingly, a third switch 218 would be actuated by the transferdevice 132 when the latter is in its rightmost position so as toindicate that particular location of the device 132. Many otherarrangements are, of course, possible insofar as providing the necessarysignals to the driver is concerned.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:
 1. Valve control means comprising:anaxially reciprocable stem adapted for force-transmitting connection to avalve; means coupled with said stem for effecting said reciprocationthereof; a pair of shoulders spaced along said stem and movabletherewith between a pair of opposite, operated positions; and a pair ofblocking bars offset in an axial direction relative to said stem forrespective ones of said shoulders, each of said bars being shiftableindependently of the other transversely of said stem into and out of aposition between said shoulders blocking movement of its correspondingshoulder to said operated position thereof.
 2. Valve control means asclaimed in claim 1, wherein said shoulders and said bars are so disposedthat the stem is held in a neutral position between said operatedpositions when both bars are in said blocking positions.
 3. Valvecontrol means as claimed in claim 2, wherein said shoulders are providedwith opposed chamfers facilitating insertion of the bars therebetween.4. Valve control means as claimed in claim 3, wherein each of said barshas a beveled end further facilitating insertion of the bars between theshoulders.
 5. Valve control means as claimed in claim 1; and a reliefspring coupled with said reciprocation-effecting means for relievingstress in the latter when actuation thereof is blocked by one or both ofsaid shoulders being in their blocking positions.